ATF4 is a basic zipper transcriptional regulatory factor. Levels of ATF4 protein increase in response to eIF2 phosphorylation during amino acid starvation or ER stress. Enhanced levels of ATF4 induce a cascade of transcriptional regulators including CHOP/GADD153 and ATF3, contributing to a program of stress gene expression important for cellular metabolism, the redox status of the cell, and apoptosis. The 5'untranslated region includes two uORFs, the first encodes a polypeptide only three ami......